GB844789A - Chlorine manufacture - Google Patents

Abstract

Gaseous nitrogen dioxide is reacted with agitated solid ammonium chloride particles in the presence of an amount of water equal to less than 5% by wt. of the ammonium chloride to yield nitrosyl chloride which is subsequently oxidised by known methods (as exemplified) to give chlorine and regenerate nitrogen dioxide. Nitrogen dioxide, diluted if desired with N2 or air e.g. as in gases obtained during the catalytic oxidation of ammonia, is passed preferably at a low temperature e.g. 21 DEG C., at atmospheric pressure, over agitated solid ammonium chloride either alone or in admixture with sodium chloride with an amount of water which is between 2.0-0.25% by wt. of the ammonium chloride. Reference is made to the subsequent oxidation of nitrosyl chloride by mixing it with oxygen and passing the mixture over a silica or alumina catalyst at a temperature of 200-250 DEG C. and separating chlorine and nitrogen dioxide by fractional distillation of the liquefied oxidation products.